Engineers at Northwestern University in Illinois have discovered a groundbreaking method to store carbon dioxide (CO2) in concrete while maintaining its strength and durability.
The new process, which uses carbonated water instead of still water during manufacturing, could help mitigate the significant CO2 emissions from the cement and concrete industries.
In laboratory experiments, the team achieved a remarkable CO2 sequestration efficiency of up to 45 per cent, capturing nearly half of the CO2 injected during concrete production.
This innovation could potentially offset a portion of the 8 per cent of global greenhouse gas emissions attributed to these industries.
The study, published in Communications Materials, was led by Alessandro Rotta Loria, Louis Berger Assistant Professor of Civil and Environmental Engineering at Northwestern’s McCormick School of Engineering.
The research was conducted in collaboration with CEMEX, a global building materials company focused on sustainable construction.
Rotta Loria emphasised the simplicity and potential impact of their approach: “We now have a new method to reuse some of the CO2 emitted as a result of concrete manufacturing in this very same material.
“And our solution is so simple technologically that it should be relatively easy for industry to implement.”
The process involves injecting CO2 gas into water mixed with a small amount of cement powder before combining it with the remaining ingredients.
This carbonated suspension results in concrete that absorbs CO2 during its manufacturing process.
Crucially, the new concrete maintains its strength and durability.
Rotta Loria noted: “Based on our experiments, we show the strength might actually be even higher. We still need to test this further, but, at the very least, we can say that it’s uncompromised.”
This means that carbonated concrete could be used in all traditional applications, from beams and slabs to columns and foundations.
Davide Zampini, vice president of global research and development at CEMEX and study co-author, highlighted the broader potential of this approach: “This provides an opportunity to engineer new clinker-based products where CO2 becomes a key ingredient.”
As the concrete industry grapples with its environmental impact, this innovative process offers a promising path towards more sustainable construction practices.
With further development and industry adoption, it could play a significant role in reducing the carbon footprint of one of the world’s most widely used materials.
